The present invention relates to a method for purification of waste gas or outgoing air with dry, powdery or granular sorbent at less than about 500.degree. C. in a low temperature stage, in which acidic and/or oxidizable noxious gaseous components such as, for example, SO.sub.x, HCl, HF, NO.sub.x, CO, and C.sub.n H.sub.m are bound to the sorbent giving off oxidizing radicals, in particular OH*. The waste gas is at least partially freed of flue dust before entering the low temperature stage and contains at least two percent (by volume) oxygen. The present invention is also directed to an arrangement for carrying out this type of method.
It has been known to remove noxious gaseous components from waste gases with sorbent, the essential requirement being that the sorbents are blown into the waste gas in superstoichiometric ratio, with disposal of the used, relatively uncharged (unloaded), but yet unusable sorbent. The consequences are relatively large disposals which give rise to attendant difficulties.